1. Technical Field of the Invention
The present invention relates to an optical disc apparatus and, more particularly, to a structure for holding a tray for loading and unloading an optical disc.
2. Description of the Related Art
A known optical disc apparatus incorporates a structure that uses an engagement lock pin having substantially a predetermined thickness for holding a tray in position and has a lock arm, a hook portion of which is pressed substantially at right angles against a surface. Accordingly, if an impact force is applied to the apparatus, a large force is applied from the hook portion to the lock pin, resulting very often in a damaged hook portion or lock pin. In association with the present invention, known art for improving impact resistance of the apparatus includes techniques disclosed in, for example, Japanese Patent Laid-open No. 2000-76766, Japanese Patent Laid-open No. Hei 10-83651, and Japanese Patent Laid-open No. 2004-227702. Japanese Patent Laid-open No. 2000-76766 discloses an arrangement as a tray lock mechanism in a disc drive or the like, in which a sliding portion of a lock lever is formed into an arc having a center at a pivot of the lock lever, thereby preventing a tray in a condition of being fixed to a chassis from being unlocked even when an impact is applied thereto. Japanese Patent Laid-open No. Hei 10-83651 discloses an arrangement as a shutter lock mechanism for a disc cartridge, in which the disc is protected from possible damage by making a shutter member disengageable from an engagement portion of a shutter lock member when an impact is applied. Japanese Patent Laid-open No. 2004-227702 discloses an arrangement, in which, should an impact force be applied in a direction of ejecting a tray from a main body unit, an urging force of a resilient member lessens a force to be applied to a lock arm and a rib, or the lock arm is rotated so as to allow a hook portion to be disengaged from the rib.
In any of the foregoing conventional arrangements, however, disengagement of the lock arm or the lock lever is accomplished, when the impact force is applied to the optical disc apparatus, through displacement of the lock arm or the lock lever in a plane of rotation thereof. This could necessitate installation of an addition part for disengagement operation, or make the structure concerned complicated.
It is therefore an object of the present invention to ensure that, in an optical disc apparatus with a simplified structure incorporating a small number of parts, no parts will be damaged even when an impact is applied thereto.
An advantage of the present invention is to provide an optical disc apparatus offering an outstanding impact resistance.